The present invention relates to Internet telephony, i.e., placing telephone calls over a specific secondary network, such as the Internet, by way of a standard telephone connection using the Public Switched Telephone Network (PSTN).
The technique of using the Internet to carry on telephone communications is commonly referred to as Internet Telephony (IT) or, sometimes, Voice on the Net (VON). IT is a way to communicate over the Internet that bypasses PSTN toll connections. IT can be advantageous for individuals and businesses that need or want to communicate extensively with others outside of their local calling areas, especially to frequently called numbers.
IT is typically accomplished by what is commonly referred to as Personal Computer-Based Internet Telephony (PCIT). PCIT allows users with properly equipped personal computers to complete long distance telephone calls to one another over the Internet without incurring a toll charge. To do so, the users must have personal computers that are multimedia capable in terms of possessing a sound card, sufficient processing power, a high quality microphone, an adequate modem (preferably 14.4 or faster) and the same specialized software programs, as well as an account with an online service or Internet service provider (ISP) for connection to the Internet via SLIP (the serial-line Internet protocol) or PPP (the point-to-point protocol). Current PCIT techniques are not compatible with shell accounts, which are accounts in which a user logs on through terminal emulation to a remote machine running Unix or the like and accesses the Internet through that remote machine in text mode by typing commands at a prompt
Several PCIT software packages are on the market. These packages are mutually incompatible; two users wishing to make a PCIT connection must have the same software package. Popular PCIT software packages include those marketed under the names xe2x80x9cIphonexe2x80x9d and xe2x80x9cWeb Phone.xe2x80x9d
The xe2x80x9cWeb Phonexe2x80x9d software works in the following manner. The users wishing to speak to each other must both be online for the communication to take place, although they can arrange beforehand to be online at the same time.
Both users run the software, and the software packages on both computers seek each other by referring to each other""s Internet protocol (IP) addresses. An IP address can be static, meaning that each user is assigned a single permanent IP address, or dynamic, meaning that a user is assigned a different IP address every time that user logs on. If the users both have static Internet protocol addresses, they can simply store each other""s IP addresses beforehand. However, many users, including virtually all users of less expensive ISP""s and of online services such as America Online, have dynamic IP addresses. Therefore, before the users can connect to each other, they must log onto a common server so that each one can find out the dynamic IP address which has been assigned to the other user. Either way, once the users have each other""s IP addresses, the software packages can communicate with each other over TCP/IP (transfer control protocol/Internet protocol) ports 21845, 21846 and 21847.
Sound originating on one end is digitized via the microphone and sound card, compressed, and transmitted to the other end as packets over the Internet using TCP/IP, where the packets are decompressed and converted back into sound via the sound card and speakers.
There are, however, disadvantages associated with the present state of IT or VON. Besides the hardware requirements and the difficulty that many users have with configuring their computers to achieve SLIP or PPP connections to their ISPs, until such time as PCIT vendors can agree on standards, the requirement that both users have the same software to communicate with each other will remain. Not only is the hardware described above expensive, but extensive knowledge of computers and the Internet is also required, making IT intimidating to a majority of the population who would otherwise like to take advantage of this capability. There are other disadvantages to PCIT. Its users need to prearrange a time to call each other because both parties must take proactive measures to connect the call and thereby converse with each other.
Internet Telephony also sometimes refers to a new service being planned whereby individuals or businesses may use or pre-subscribe to a special access number and place their long distance telephone calls by way of a long distance carrier who uses the Internet to carry the calls. This service eliminates most of the disadvantages of PCIT, but also eliminates most of the advantages, in that toll and/or usage type charges still apply.
Devices are known for allowing PCIT by letting users initiate a conversation over the PSTN and switching to IT. Such devices exchange information relating to their IP addresses during the PSTN phase of the call so that the IT phase of the call can be completed. However, in such devices, the modem may be set or initialized twice, once for the PSTN phase of the call to exchange the IP address information and once for the IT phase of the call to connect to the Internet. Setting the modems twice is time-consuming. Also, such devices cannot be used for calls which take place entirely by way of IT, since they have no way of exchanging the IP address related information to locate each other.
It is an object of the invention to allow a user to make telephone calls via the Internet without a need for an expensive multimedia-capable personal computer.
It is another object of the invention to allow a user to make telephone calls via the Internet without a need to configure such a computer for a SLIP or PPP connection to the Internet.
It is a further object of the invention to allow a user to select a route for a telephone call (the Internet, the conventional PSTN, a dedicated network, etc.) and to use a single device for the call regardless of which route is selected.
It is a further object of the invention to provide a device and method for Internet telephony which are easy to use, do not require a computer and offer superb voice quality.
To these and other ends, the present invention is directed to a terminal device or Internet switch box (ISB) for connecting a first telephone set and a second telephone set over a selected one of a primary network and a secondary network, the switch box comprising: primary network connecting means for connecting the first telephone set to the primary network; secondary network connecting means for connecting the first telephone set to the secondary network and for establishing a connection over the secondary network between the first telephone set and the second telephone set; relay means for (i) connecting, when the relay means is in a first state, the first telephone set to the primary network connecting means and for (ii) connecting, when the relay means is in a second state, the first telephone set to the secondary network connecting means; and switching means for receiving a switch-over command to switch from the primary network to the secondary network and for controlling, in response to the switch-over command, (i) the relay means to disconnect the first telephone set from the primary network connecting means and to connect the first telephone set to the secondary network connecting means and (ii) the secondary network connecting means to establish the connection over the secondary network between the first telephone set and the second telephone set.
A relatively inexpensive interface device, referred to as an Internet switch box (ISB), is connected to or integrated within the telephone. While the user must possess access to the Internet either directly or via an Internet Service Provider (ISP) in order to use the ISB, the user will not be subject to toll charges other than those incurred using the PSTN to establish the Internet telephone call. The user does not need to understand how a computer works or how to use any PCIT software, since the ISB can be preprogrammed to dial an ISP and to connect via SLIP or PPP. The user need only know how to dial the call using normal PSTN dialing procedures and then simply switch the call to an Internet connection, if available and desirable. Other than the user pressing a button (either on the ISB or telephone keypad) to initiate the Internet telephone call, the ISB takes care of all connection procedures (i.e., handshaking) necessary to set up and maintain the Internet telephone call. While both parties must possess an ISB in order to take advantage of the ISB""s IT capabilities, only one party needs to initiate the telephone call in order to establish the Internet connection, so that prearrangement is not required.
Advantageously, the selection among networks may be among the PSTN, selected proprietary networks, or the Internet. It should be noted that the PSTN utilizes circuit switching techniques whereas, for instance, the Internet makes use of packet switching. Circuit switching was specifically designed and is best for analog voice transmissions, whereas packet switching was designed and is best for digital data transmissions. Regardless, either type of switching may be employed for voice or data. The calling party uses the PSTN to first establish the connection between calling and called parties, and then the two parties decide whether or not to use their ISB""s to re-establish the connection via a secondary network such as the Internet. The users will consider convenience, cost and connection quality in making this choice. If the telephone call is to another party in the same local calling area, of short duration, or one where, regardless of cost, the stability and voice quality of the connection are essential, then the users typically opt to stay on the PSTN connection and not seek to switch to the Internet. Otherwise, the potential cost savings of simply switching to an Internet connection make doing so preferable.
As indicated, an ISB may be incorporated into a telephone or be a standalone adjunct device connected between the telephone and the telephone line. Additionally, ISB""s may be associated with facsimile machines, wireless telephones and multiple line telephone systems, such as key telephone and Private Branch Exchange (PBX) systems, and operate to provide multiple users of such Customer Provided Equipment (CPE) the ability to designate the secondary network handling of their toll calls. According to one embodiment, the ISB will set up a secondary network or Internet telephone call after the PSTN connection has been established and in response to a command to do so by its user(s) as described above. In an alternative embodiment, the ISB may be configured to establish a connection over a secondary network automatically unless commanded not to prior to the call being placed. In either case the called telephone can answer or simply ring before the telephone call can be switched to a secondary network or the Internet. As such, the ISB does not interfere with accepted and customary PSTN procedures in that the PSTN portion of the telephone call is billable only if there is an answer by a live person or an answering machine or voice mail service.
In order to establish a secondary network or Internet connection via the ISB, the user will first dial the PSTN telephone number of the intended call recipient. Once the called telephone is answered, which is a billable PSTN telephone call of short duration, both parties initiate, via a simple key stroke, the switch to the secondary network. The two ISB""s disconnect the PSTN call, and each initiates its own call to the other via the secondary network. If the secondary network is the Internet, the connection typically is by way of an Internet Service Provider (ISP) which can be reached, advantageously, by a toll-free telephone call enabling access to the user""s Internet service account which, advantageously, has unlimited use or use charges in an amount much lower than the expected PSTN charges. The two ISB""s possess information (i.e., addresses, passwords, etc.) necessary to re-connect the telephone call via the secondary network. Each ISB can be programmed to provide call progress tones or to play pre-recorded messages, music, etc., while the users await reconnection. If the call cannot be connected via the secondary network due to access problems at the ISP or otherwise, then each party is so informed by a recognizable audio signal such as a busy signal or a voice recording. Either or both parties can, by pressing appropriate keys, retry their connection via the Internet or reconnect the telephone call over the PSTN. This capability is somewhat analogous to the redial capability on many conventional telephones. Should two parties seek to avoid PSTN charges altogether, they may use this same capability to do so via prearrangement. In so doing, each party need only input the other party""s telephone number in addition to pressing the appropriate buttons on the ISB or telephone keypad. Regardless, once the call is connected via the secondary network or the Internet, the parties terminate the call by hanging up, as with any PSTN call.
The present invention thus implements an embedded approach to IT which offers the following advantages. The use of ISB""s allows low-cost, easy-to-use, embedded Internet access for telephones. Lower cost is achieved because no PC""s are required. Users, many of whom would prefer not to have to configure a PC for Internet access, are offered a familiar PSTN approach which can identify a called party by that party""s existing telephone number. This approach also preserves the major advantage of IT, namely, the use of low-cost Internet bandwidth.
While the invention is intended primarily for use with single-line analog telephone sets, it can be adapted for use with other telephone systems, such as DID PBX (direct-in-dial private branch exchange) and Centrex service and with analog or digital mobile telephones such as cellular telephones and PCS personal communication service) telephones. Also, while the ISB can be built to access the ISP through a dial-up connection, it can alternatively be built to access the ISP through another connection, such as an ISDN (integrated services digital network) connection or a cable modem connection.